Effect of hydrogen-isotope implantation on aluminum oxide tunnel-junction barriers

Abstract

This paper compares aluminum oxide tunnel junctions prepared by standard plasma techniques with those made with the use of an ion gun. The effect of hydrogen and deuterium implantation on the barriers has been studied in detail both in terms of the inelastic electron tunneling spectra and the change in work function produced at the metal-oxide interfaces. The results indicate that there is an upper limit on the amount of hydrogen which may be present in the oxide barrier. The results further suggest that the peak in the inelastic electron tunneling spectrum at 230 meV (1850 ${\mathrm{cm}}^{\ensuremath{-}1}$) may be due to aluminum hydride.